What is Myotonia

A breed description is different from most breed standards in that a description describes, while a standard prescribes. The Myotonic goat, a landrace breed, is more varied than standardized goat breeds - especially so if it is compared to imported breeds that were started with relatively few goats that all had very similar traits. A landrace type of population means that the Myotonic goat breed survived (and many still do) as an untracked and unmonitored population of locally used goats for local production purposes. Imported and standardized breeds in the US include nearly all the Dairy breeds along with the Angora and Boer goat. This breed description is lengthy, and tries to be very specific so that breeders can understand just exactly what a Myotonic goat is, and why the breed is more than the single trait of myotonia. The general organization of this document provides a short descriptive piece followed by a comment that explores the practical reasons for the importance of the description and its relation to Myotonic goats. INTRODUCTIONThe Myotonic goat is a distinct breed yet it has many synonyms for names, including Nervous Goats, Wooden-Leg Goats, Scare Goats, Fainting Goats, and Tennessee Fainting Goats. The breed is a multi-purpose goat derived from a variety of strains of goats that were originally from Tennessee. As is typical of locally developed breeds, the overall type and conformation do vary somewhat more than is typical of imported, standardized breeds (dairy breeds, Angoras, Boers). However, the breed does have several distinctive features that set them apart from other goat breeds, and it is these features that help to define the Myotonic goat as a breed. Several old strains of Myotonic goats persisted in Tennessee, and goats of these lines can still be found. In addition, several lines developed in Texas since the 1950s, and some of these have a slightly different “look” by virtue of being selected in a different environment and for different goals. One must remember that the Texas goats ultimately originated in Tennessee and so both strains are indeed branches of the same breed. The relatively newer strain of the breed is the minis. The mini Myotonic goats retain the distinctive breed features, though in a more compact and shorter size. They too ultimately originated in Tennessee, just as the Texas strain, and so too are a branch of the same Myotonic breed.Myotonic goats have a very distinctive breed type that is based mostly on head and body conformation. They also have a muscle condition called myotonia congenita. This inherited trait leads to an overall increase in muscle mass so that the goats are very muscular when compared to other breeds of similar size. This trait is so distinctive that it is easy to confuse the trait with the breed. However, the Myotonic goat is much more than just a myotonic condition; it has a host of other consistent traits that are very important and need to be conserved for future generations.Several important characteristics are typical of the breed:1. Docile temperament2. Myotonia congenita leading to stiffness and muscularity3. Abundance of high quality muscle4. Good adaptation to low-input forage-based feeding systems5. Genetic distance from other breeds such that crossbreeding yields great hybrid vigor.Comment: The usefulness of Myotonic goats depends on their being maintained as a pure breed resource, distinct from other breed resources. This requires attention to breed type and breed history. It is also critically important to understand that the breed is more than the myotonia, because crossbred goats can indeed be myotonic. Understanding that the breed needs to be maintained as a pure breed resource is the reason for tracking crossbreeds that carry and/or show myotonia. In general this is a relatively slow-growing breed with great ability to be maintained and developed on a forage-based system. Crossbreeding of these goats will increase growth rates, though size increase or decrease is variable depending on the breed which was used in the crossbreeding; however, crossbreeding will eliminate their genetic distinctiveness and therefore their long-term utility. Their distinctiveness and usefulness lie in their being maintained as a pure breed resource. Current uses include both commercial meat production, as well as companion animals (pets). GENERAL DESCRIPTIONMyotonic goats come in varying sizes. The medium to large animals of this breed are generally used for meat production while the smaller animals are generally sought after as pets. Myotonic goats of all sizes are stocky, with obvious width for height. The body is wide, full, and deep, with heavier than average muscling evident throughout. Muscle development increases with age, so that older goats are more heavily muscled than younger ones. Tennessee bloodlines tend to be lower and broader than Texas bloodlines, which tend to be taller and a little less blocky. They are alert, good-natured animals with a conformation that is smooth, functional, and rugged. They are also generally quiet, and are much quieter than many other breeds of goats. Parasite-resistance is another trait that the breed is renowned for.Comment: The overall appearance of these goats is important, although extremes within the breed should be avoided. Myotonic goats are ideally blocky and stocky, and are distinct from most other breeds in this conformation. However, extreme blockiness can result in difficult kidding and poor mobility in range conditions. Thinly fleshed goats or those with a very delicate and refined conformation are atypical for the breed. Even the mini strain of the Myotonic breed generally holds true to carrying a more blocky and stocky appearance than breeds of similar size. Abnormally thick goats can have mobility problems and should therefore be avoided.